A communication device comprising: a wireless communication section; and a control section configured to correlate a first signal with a second signal from another communication device at a designated interval, convert a data matrix including an array of a plurality of correlation computation results into a format including a matrix product of an expanded modal matrix and an expanded signal matrix, estimate the expanded signal matrix that minimizes a predetermined norm, and estimate reception time of the second signal on a basis of the expanded signal matrix that minimizes the predetermined norm.

Integrated circuits may include a constant false alarm rate (CFAR) detection circuit, which may identify targets among clutter and noise in a range-Doppler map. The CFAR detection circuit may compute power values for each cell in the range-Doppler map and scan the range-Doppler map cell by cell. For this purpose, the CFAR detection circuit may compute a target value for a cell-under-test and surrounding cells and a noise value for one or more regions in local proximity of the cell-under-test on the range-Doppler map. For example, the CFAR detection circuit may perform a two-dimensional filtering to compute the target value and compute a sum of accumulated power values weighted by predetermined coefficients. The predetermined coefficients may taper at edges of the range-Doppler map and/or at edges of the regions. The CFAR detection circuit may declare a target based on a comparison of the target value and noise value.

A radar processor for processing a frame of radar data received from one or more targets, the frame of radar data having a carrier frequency and comprising a sequence of codewords with a codeword repetition interval, wherein the carrier frequency and the codeword repetition interval define an unambiguous velocity range, the radar processor configured to: receive the frame of radar data; transform the frame to obtain a velocity data array; apply a correction algorithm to the velocity data array to correct a Doppler shift of the frame to obtain a corrected array, wherein the correction algorithm comprises a set of Doppler correction frequencies corresponding to a set of velocity gates and at least one of the set of Doppler correction frequencies corresponds to a velocity gate outside the unambiguous velocity range; and perform range processing on the corrected array to obtain a range-Doppler map.

A radar processor for processing a frame of radar data received from one or more targets, the frame of radar data having a carrier frequency and comprising a sequence of codewords with a codeword repetition interval, wherein the carrier frequency and the codeword repetition interval define an unambiguous velocity range, the radar processor configured to: receive the frame of radar data; transform the frame to obtain a velocity data array; apply a correction algorithm to the velocity data array to correct a Doppler shift of the frame to obtain a corrected array, wherein the correction algorithm comprises a set of Doppler correction frequencies corresponding to a set of velocity gates and at least one of the set of Doppler correction frequencies corresponds to a velocity gate outside the unambiguous velocity range; and perform range processing on the corrected array to obtain a range-Doppler map.

A radio detection and ranging (radar) operating apparatus includes: radar sensors configured to receive signals reflected from an object; and a processor configured to generate Doppler maps for the radar sensors based on the reflected signals and estimate a time difference between the radar sensors based on the generated Doppler maps.

A radio detection and ranging (radar) operating apparatus includes: radar sensors configured to receive signals reflected from an object; and a processor configured to generate Doppler maps for the radar sensors based on the reflected signals and estimate a time difference between the radar sensors based on the generated Doppler maps.

This disclosure relates generally to material quality inspection. Conventional approaches available for material quality inspection are unable to address concerns of complexity and cost involved. The technical problem of occluded object detection and material quality inspection for intrinsic defects identification is addressed in the present disclosure. The present disclosure provides a system and method for non-intrusive material quality inspection using three-dimensional monostatic radar based imaging, where the object under inspection undergoes a circular translation motion on a rotating platform. A modified delay-and-sum (m-DAS) algorithm is built by incorporating virtual antenna array to obtain a 3D image reconstruction of the object. From 3D reconstructed images, radial displacement as well as the angular locations of the object is identified which are further used for quality inspection of the material comprised in the object.

This disclosure relates generally to material quality inspection. Conventional approaches available for material quality inspection are unable to address concerns of complexity and cost involved. The technical problem of occluded object detection and material quality inspection for intrinsic defects identification is addressed in the present disclosure. The present disclosure provides a system and method for non-intrusive material quality inspection using three-dimensional monostatic radar based imaging, where the object under inspection undergoes a circular translation motion on a rotating platform. A modified delay-and-sum (m-DAS) algorithm is built by incorporating virtual antenna array to obtain a 3D image reconstruction of the object. From 3D reconstructed images, radial displacement as well as the angular locations of the object is identified which are further used for quality inspection of the material comprised in the object.

A radio detection and ranging (radar) operating apparatus includes: radar sensors configured to receive signals reflected from an object; and a processor configured to generate Doppler maps for the radar sensors based on the reflected signals and estimate a time difference between the radar sensors based on the generated Doppler maps.

A radio detection and ranging (radar) operating apparatus includes: radar sensors configured to receive signals reflected from an object; and a processor configured to generate Doppler maps for the radar sensors based on the reflected signals and estimate a time difference between the radar sensors based on the generated Doppler maps.